
class MyCounter {
    public int a;

    public static int count = 0;
    synchronized public void add() {
        count++;
    }
}
public class Test7 {
    //对方法加锁


    public static void main(String[] args) throws InterruptedException {
        MyCounter counter = new MyCounter();
        Thread t1 = new Thread(()->{
            synchronized (counter) {
                for (int i = 0; i < 50000; i++) {
                    counter.add();
                }
            }
        });
        Thread t2 = new Thread(()->{
            synchronized (counter) {
                for (int i = 0; i < 50000; i++) {
                    counter.add();
                }
            }
        });
        t1.start();
        t2.start();
        t1.join();
        t2.join();
        System.out.println(MyCounter.count);
    }
}
